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1.
Dalton Trans ; 50(12): 4390-4395, 2021 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-33704335

RESUMO

Gold(i) bridged dimeric and trimeric structures of a ground state spin S = 1/2 heterometallic {Cr7Ni} wheel have been prepared and studied by continuous wave (CW) and pulsed wave EPR spectrometry. The {Cr7Ni} relaxation time constants (T1 and Tm) show rates matching well with previous observations. Four pulse Double Electron Resonance (DEER) studies suggest presence of more than one conformations. Small Angle X-ray Scattering (SAXS) in conjunction with Molecular Dynamic (MD) Simulations were performed to look at the possible conformations in solution. In line with DEER results, simulation data further indicated more flexible molecular geometry in solution than the one in solid state.

2.
Angew Chem Int Ed Engl ; 55(31): 8856-9, 2016 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-27294807

RESUMO

The first regular homometallic ring containing an odd number of metal centers is reported. The ring was synthesized by means of amine-templated self-assembly. Extensive physical characterization studies, including magnetic measurements, powder inelastic neutron scattering (INS), and DFT calculations, show that the molecule has a near perfect match to the expected behavior for a frustrated system with the lowest energy pair of S=1/2 spin states separated by only 0.1 meV (0.8 cm(-1) ).

3.
Proc Natl Acad Sci U S A ; 109(47): 19113-8, 2012 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-23132941

RESUMO

The term "frustration" in the context of magnetism was originally used by P. W. Anderson and quickly adopted for application to the description of spin glasses and later to very special lattice types, such as the kagomé. The original use of the term was to describe systems with competing antiferromagnetic interactions and is important in current condensed matter physics in areas such as the description of emergent magnetic monopoles in spin ice. Within molecular magnetism, at least two very different definitions of frustration are used. Here we report the synthesis and characterization of unusual nine-metal rings, using magnetic measurements and inelastic neutron scattering, supported by density functional theory calculations. These compounds show different electronic/magnetic structures caused by frustration, and the findings lead us to propose a classification for frustration within molecular magnets that encompasses and clarifies all previous definitions.

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